1. Field of the Invention
This invention relates to a ground-free device for removing static electrical charge from a conductive or semi-conductive body, and particularly a device of such type which may be
worn on the human body in a compact form; or PA1 mounted on transportation vehicles, such as cars and aircrafts, for removal of static charges therefrom.
2. Description of the Related Art
While the present invention is broadly useful for removing static electrical charge from conductive and semi-conductive charged bodies, two specific applications are in particular concern:
The first application is the discharge of static electricity from the human body. Historically, a number of means and methods have been developed for "grounding" the human body to dissipate static electricity therefrom. Typically, these approaches have utilized wire connections for attaching the body to a large metallic object (or true ground), to utilize the surplus of positive/negative charges in the metallic object to neutralize the body. These approaches, while effective to preclude the build-up of static charge in the bodies of individuals, suffer from the disadvantage that mobility thereby is severely circumscribed, as well as dexterity which in many instances is required to perform functions or tasks desired of the "grounded" individual.
The second application is related to transportation vehicles (cars and aircrafts). It is known that static electricity build-up during the movement of these vehicles is responsible for pains, fatigue, and drowsiness of passengers, as well as damage of electronic equipment in the vehicle. Historically, chains and conductive rods, attached to the bodies of these vehicles, have been used to drain static charges by means of friction with the surrounding medium (air or asphalt). These approaches, apart from being ineffective, suffer from the great disadvantage that friction produce sparks, and eventually can result in a fire, especially in the case of automobiles.
Apart from corporeal, or transportation-related applications, a number of systems have been devised in the art to preclude static electricity build-up.
U.S. Pat. No. 3,634,726 issued Jan. 11, 1972 to Pierre Jay describes an apparatus for removing static electricity from plastic films. The apparatus requires a ground connection.
U.S. Pat. No. 4,523,252 issued Jun. 11, 1985 to J. O. Wallen describes a device for eliminating static electricity on machines and charged materials. The device depends on the operation of a tunnel diode, and must be connected between charging media and the machine part.
U.S. Pat. No. 4,180,698 issued Dec. 25, 1979 to R. B. Carpenter describes a system for protection of objects located on the surface of the earth from the effects of atmospherics.
U.S. Pat. No. 4,766,903 issued Aug. 30, 1988 to Herbert Esper describes a device for detecting and removing static charges from the human body. The device, however, requires a ground connection.
U.S. Pat. No. 4,849,851 issued Jul. 18, 1989 to R. J. Cubbison, Jr. describes a static electric discharge device which may be contained in a wrist-mountable unit. The device uses a high electric field to ionize the air molecules. The Cubbison, Jr. patent suffers various deficiencies in use, and will not achieve its intended purpose of effectively removing charges from the body, mainly for the following two reasons:
1. It is claimed that the electric field of the body can separate the closely-spaced positive and negative ions of the air. In fact, the electric field at any particular point on the skin is negligibly small, because the charge is distributed all over the body (that is why a high electric field is used to ionize the air in the first place). For that reason, the claimed effect is very slow in nature.
2. From an electric-circuit view point, a more significant deficiency is apparent. This deficiency is simply the use of a DC voltage from a power supply. It is clear that whether the air is near or at the breakdown point, a small current will flow in the circuit because the circuit is "closed". This by no means will result in the withdrawal of charges from the body, since, in this case, the ions of the air are themselves the current carries. In summary: "Static charges cannot flow into a closed electrical circuit".
Accordingly, it would be a significant advance in the art to provide a ground-free device for removing static electrical charge from the human body and from other conductive or semi-conductive bodies, which is characterized by a high static charge removal efficiency, e.g., levels of at least 95%, in a small fraction of a second. This is the object of the present invention.